D efficiency

[#1]

I am new to JMP. In DOE, what is the significance of D efficiency and I efficiency. When I make a custom design model, should the D efficiency be under or over certain value for my design to be useful? In a model I made my D-efficiency is 74 % what does this mean? My design is good/bad/okay?

[#2 · Accepted solution]

The measures of efficiency are scaled between 0 to 100

The efficiency is a measure of the goodness of a design relative to a hypothetical orthogonal design so they are not useful as absolute measures. They should be used in a relative fashion to compare one design to another. Efficiencies that are less than 100 may be perfectly satisfactory.

[#3]

A great book on this topic is titled Optimal Design of Experiments by Peter Goos and Bradley Jones.

A key quote from the book with regard to this topic is

"do not recommend focusing on D-efficiency...we find it useful to compute relative D-efficiencies to compare competing designs"

[#4]

Thanks a lot LouV. It helps me to feel better about my design!!!

[#5]

I have multiple designs with D, G and A Efficiencies of 100%. Since 100% is not possible are these good designs or should I reassess the number of factors and runs to obtain a more reasonable %? 

[#6]

100% efficiencies are possible. Your designs are likely just fine.